The present invention relates generally to an air flow control device for a vehicle, especially for an automotive vehicle. More specifically, the invention relates to a vehicular air flow control system which has an air flow control fin with a variable inclination.
It is well known that a rear spoiler fin can effectively divert air flowing along the vehicular body, which would otherwise generate lift, so as to generate a downward force to enhance the traction of the vehicular wheels. It is also well known from the disclosure of the Japanses Utility Model First Publication (Jikkai) Showa 48-13939, that an air flow guide or control fin guiding air flow along a rear window surface can effectively wipe the outside surface of a window free of rain water, dust and so forth by the effect of the diverted air flow.
However, the latter mentioned air flow guide fin may adversely affect the aerodynamics of the vehicle and generate upward lift, especially when the vehicle speed is relatively high. Therefore, this air flow guide fin is considered effective only when the vehicle is travelling at relatively low speeds in which case, significant body lift will not occur. On the other hand, while the vehicle speed is relatively low, the rear spoiler will not have any significant aerodynamical effects, since the downward force exerted on the vehicle body through the spoiler fin will be relatively weak.
Thus, it has been observed that an air flow guide which can guide air flow along the rear window external surface while the vehicle is moving at a relatively low speed and which is also able to serve as a rear spoiler when the vehicle speed is relatively high, would be useful both for clearing the rear window and for enhancing the aerodynamics of the vehicle.
It would be even more convenient if the air flow control or guide fin inclination could be adjusted depending upon the vehicle driving conditions or under the control of the driver, especially if, the driver could control the inclination of the air flow control fin from inside the vehicle compartment or cab.